For 30 day rolling you may struggle to get that amount of data, there’s a cheeky workaround on EE that I use as they allow you to share data between plans. If you get a basic sim plan and get a mobile broadband plan you can “share” all the data to the other plan. There was a deal on there mobile broadband when I took mine out and it gave me more data for low cost than there phone plans. Just my 2 cents may not be cost effective as haven’t looked at there pricing recently.

2nd May

worth looking into. Thanks!

3rd May

Probably looking at a 3 PAYG handset sim with £25 / 30day AIO25 (30GB) or £35 AIO35 (genuinely unlimited 4G) add-on applied initially in a handset unlocked to 3. Subsequently drop the SIM in virtually any non-3-branded unlocked device / mifi. Three's t&c for handset PAYG SIMs exclude use for tethering & mifis but functionally work, so likely Three is just excluding the hassle factor of supporting non-handset devices on its handset PAYG tariffs. Buddy has been using this method for home broadband in an unlocked EE Osprey mifi for over 2 years, ocasionally racking up ridiculous bandwidth usage which probably explains why what previously cost £15 now costs £35.